Official organ of the Entomological Society of Canada (1951- ), June 1961-
Published by the Entomological Society of Canada (1863-1871), Aug. 1868-Dec. 1870; by the Entomological Society of Ontario, Apr. 1871-Dec. 1950; co-published by the Entomological Society of Canada (1951- ) and the Entomological Society of Ontario, Jan. 1951-May 1961; by the Entomological Society of Canada (1951- ), June 1961-